Lessons Learned from a Full-Scale Real World Wind Noise Modeling Project

Wind noise consistently ranks as one of the most influential factors with respect to perceived vehicle quality. In an effort to address this issue we investigated building, solving, and analyzing a CFD (Computational Fluid Dynamics) wind noise model using LES (Large Eddy Simulation) turbulence modeling. An experimental and numerical study of the effect of an actual sunroof deflector that was in place or removed from the vehicle was conducted. The combined effects of a relatively small mesh size and time step to capture the transient flow phenomena and a large number of time steps to insure valid comparisons with typical experimental results, led to extremely large solution times and a subsequent large amount of data to analyze. While good results were obtained, the practical use of this type of analysis in a development timeline was determined to be limited.